A team of experts from the U.S. will arrive in northern Mexico Tuesday, to assist in the efforts to rescue 65 miners who have been trapped since an explosion on Sunday.

Rescue crews are using hand tools to clear away the debris at the Pasta de Conchos mine in Coahuila state. Sunday's explosion was caused by gas trapped inside the mine. Officials fear using power machinery could spark another blast.

Mexico's National Miners Union is calling for an investigation into the cause of the accident.

Relatives of the 65 miners continue to hold vigil outside the mine, braving bitterly cold weather as they anxiously wait for any news about their loved ones.

The miners are believed to be about three kilometers from the mine's entrance. Officials say they were carrying a limited amount of emergency oxygen.